Numerical analysis on heat-flow-coupled temperature field for orthogonal face gears with oil–jet lubrication

Abstract

Lubrication and cooling performances of face gears with oil-jet lubrication are closely related to the nozzle layouts. To investigate the influence of the nozzle layouts on the lubrication performance of the face gears, a numerical analysis method based on heat-flow coupling is adopted in this study for predicting the transient temperature characteristics. First, a mathematical model of impingement depth integrating the nozzle spatial layouts, injection parameters, and geometric parameters of the given face gear is presented for determining the nozzle. Then, after accessing the friction heat, the heat-flow-coupled finite element model is built to resemble the oil-jet lubrication process and obtain the temperature field on the tooth surface. Finally, under the same nozzle layouts, the temperature distributions are compared with the oil pressure and oil volume fraction reported in previous studies. The results reveal that the nozzle layouts significantly affect lubrication performance. Specifically, the lubrication performance of the lateral layout parameter near the middle point of the tooth width is better, and there is a certain range for the longitudinal layout parameter and jet elevation angle. This study can provide a reference for further optimizing the nozzle layouts and prolonging the service life of the orthogonal face gear.

Lubrication Reliability and Oil Churning Loss of Differential Gear Trains in a Mechanical-Hydraulic Coupling Mechanism

“…Ouyang et al [25] investigated the jet lubrication of orthogonal face gear pair and found that a reasonable nozzle layout can improve the lubrication reliability. Hu et al [14,15] proposed a model to estimate the oil churning power loss in a helicopter spiral bevel gear transmission gearbox and analyzed how different factors affect the lubrication reliability due to oil churning.…”

Influence of Nozzle Layouts on the Heat-Flow Coupled Characteristics for Oil-Jet Lubricated Spur Gears

“…Other researchers [5,6] have come up with similar results validating through experiments that the nozzle location affects the oil-air ratio and total pressure. On this basis, the complex impingement depth model is extended for the face gear and spiral bevel gear [32][33][34]. However, the aforementioned literature determined the nozzle layouts judged by the oil-air ratio and total pressure which are hard to measure directly through an indirect method.…”

CFD investigation of air-oil two-phase flow in oil jet nozzle

“…More recently, Massini et al 6 carried out experiments on a novel rotating test bench capable of reproducing real aero-engine working conditions for single spur gear, experimental findings showed that under high Reynold number oil jet breakup happens, is detrimental for the lubrication and cooling of the target gears due to part of the oil escaping and not reaching the gear, on the other hand, the impingement velocity of oil jet reduced. By analyzing the oil jet lubrication process and meshing theory of helical/face gear pair, Dai et al 7,8 and Ouyang et al 9 further developed novel mathematical models of impingement depth closely associated with nozzle arrangement, the relationship between the measured temperature by experiments and the corresponding theoretical impingement depth indicates that a lower temperature comes with a larger impingement depth. So far, experimental researches on the detail of the flow field from the nozzle to the target parts are relatively weak.…”